Ultrasonic transmitter



March 12, 1968 L. J. SIENKIEWICZ ET AL 3,372,669

ULTRASONIC TRANSMITTER Filed March 23, 1964 2 Sheets-Sheetl WITNESSES INVENTORS Leon J. Sienkiewicz and Harry T. Go stein March 12, 1968 J, s KlEwmz .ET AL 3,372,669

ULTRASONIC TRANSMI TTER Filed March 23, 1964 2 Sheets$heet 2 United States Patent Otlice 3,372,559 Patented Mar. 12, 1968 3,372,669 ULTRASONIC TRANSMITTER Leon J. Sienkiewicz, Metuehen, and Harry T. Goldstein,

Teaneck, N.J., assiguors to Westinghouse Electric Corporatiou, Pittsburgh, Pa., a corporation of Pennsylvania Filed Mar. 23, 1964, Ser. No. 353,668 5 Claims. (Cl. 116-137) The present invention relates to a transmitter for generating ultrasonic signals and more specifically to a mechanical resonator or vibrator that generates a plurality of ultrasonic signals having predetermined discrete frequencies in the supersonic or ultrasonic range.

Ultrasonic transmitters are utilized to actuate various devices remotely. Most common of these uses is to remotely control television sets although there are various other applications for such remote control devices. In patent application Ser. No. 170,157, filed Ian. 31, 1962, in the name of Arthur Nelkin, Robert A. Lester, Robert H. Whittaker and John H. Thompson, entitled, Ultrasonic Generator, now U.S. Patent No. 3,194,209, there is disclosed a new and improved mechanical resonator or vibrator for producing an ultrasonic signal of a predetermined frequency. The resonator described therein vibrates in the fiexural mode with a plurality of nodal diameters to produce the ultrasonic signals. The signal produced by one of these vibrators will have a predetermined frequency depending upon the dimensions of the vibrator. In copending patent application Ser. No. 190,118, filed Apr. 25, 1962, in the name of Robert H. Whittaker and John H. Thompson, entitled, Ultrasonic Generator, now U.S. Patent No. 3,157,151, there is disclosed another mechanical vibrator which vibrates in the fiexural mode with a plurality of nodal diameters to produce two signals having different frequencies. The vibrator disclosed therein is capable of producing two separate frequencies from a single mechanical resonator. The embodiment of the invention disclosed in the present application utilizes a resonator to produce two frequencies similar such as the resonator disclosed in the above-mentioned application Ser. No. 190,118. In order to actuate such a generator into a pure mode that is, into a vibration of only one of the frequencies, with none of the second frequency present therein, the resonator must be actuated in the plane of maximum vibration amplitude, otherwise components of the second frequency will be present in the vibration of the resonator. Since only one frequency is used at a time in the remote control of a television set or other device, the presence of the secondor undesired frequency will reduce the sensitivity of the remote receiver in discriminating the desired signal frequency.

Accordingly it is an object of the invention to provide a new and improved ultrasonic transmitter utilizing a single vibrator for generating a plurality of ultrasonic signals having discrete frequencies.

A further object of the invention is the provision of a new and improved ultrasonic transmitter which utilizes a single resonator for generating a plurality of ultrasonic signals having discrete predetermined frequencies and having a minimum of interactionbetween the signals, during viration thereof.

It is a further object of the invention to provide a new and improved ultrasonic generator which can accurately and selectively produce at least two ultrasonic signals having different predetermined frequencies.

An ultrasonic generator embodying the present invention includes a single vibrator or resonator which has at leasttwo basic fundamental resonant frequencies so as to produce therefrom two separate signals having two discrete frequencies. In addition the generator includes actuating means for selectively actuating a desired single frequency signal while at the same time greatly reducing the vibration of the resonator at other undesired frequencies.

These and other advantages of this invention will be more clearly understood from the following description when taken in conjunction with the accompanying drawing, in which:

FIG. 1 is an isometric view of an ultrasonic transmitter embodying the invention;

FIG. 2 is a side elevation view of the transmitter illustrated in FIG. 1;

FIG. 3 is a front elevation view of the transmitter illustrated in FIG. 1; and

FIG. 4 is a lower isometric view of the transmitter illustrated in FIG. 1.

In the above-mentioned U.S. Patent No. 3,194,209 there is disclosed a mechanical ultrasonic resonator or generator for producing an ultrasonic signal of a predetermined frequency. This generator vibrates in a flexural mode with a plurality of nodal diameters, to produce vibrations of a predetermined frequency in the ultrasonic frequency range. In the vibrator described therein the mounting means is an integral pin which is located at a point on the surface of the vibrator so that equal and opposite vibratory forces are applied to this pin so that no energy is lost to the pin. In the above-mentioned U.S. Patent No. 3,157,151, there is disclosed therein a mechanical resonator which employs a similar mounting pin, however, it is capable of producing two separate resonant frequencies. With no losses to the pin the free end of the mounting pin can be mounted in any manner without losses of energy through the mounting means since the energy imparted to the disk. is retained in the disk due to the cancellation afforded by the concentric mounting pin and the relatively undamp connection with the resonator. Consequently the mounting of such mechanical resonator, unlike most mechanical resonators, is not critical and can be done in any conventional man ner such as by screw threads, etc.

In the present invention a mechanical resonator capable of vibrating in two fundamental frequencies is utilized and the embodiment of the invention illustrated in the drawings utilizes a resonator similar to that described in U.S. Patent No. 3,157,151, and reference is made thereto for specific details of such a resonator.

Referring now to FIGS. 1-4, the embodiment of the invention, as shown, utilizes a single resonator having two discrete resonant frequencies, comprises a supporting assembly 54) having a cross bar 51 with rectan-gularly shaped upwardly extending recesses 53 therein. Integral with the front cross bar 51 are two rearwardly extending horizontally disposed parallel supporting arms 54. On the rear portion of the arms 54 are two horizontally disposed supporting tabs 55. These tabs have apertures therein so as to be mounted on a suitable housing. Extending downwardly from cross bar 51 is a vertically disposed leg 52 having a horizontal supporting plate 56 extending forwardly therefrom and integral therewith.

A pivot pin 57 is mounted on and between the two rearward extending supporting arms 54, adjacent the cross bar supporting member 51. The shaft 57 is secured to the arms 54 for rotation thereon by some suitable means such as a lock washer or by any other suitable means that allows rotation of shaft 57 without it being displaced from the apertures in arms 54. As shown in FIGS. 1 and 2, two leaf springs 61 and 63 are secured to the cross bar 51 and extend downwardly therefrom. These leaf springs are symmetrical with the respective recesses 53 and have a width smaller than the width of the recesses 53 so that they may pass therethrough if sufiicient backward tension is applied to the leaf springs 61 and 63 so as to swing forwardly toward the disk or resonator mounted on leg 52. Mounted on the lower portion of leaf springs 61 and 63 are strikers 62 and 64 which are secured respectively to leaf springs 61 and 63. As shown in FIG. 2 the striking face of these strikers is spherical so as to tend to contact the disk at a predetermined single point. As shown in FIG. 3, striker 62 will contact the back surface 13 of disk 10 at a point B on a diameter which is located 90 from two of the radially disposed holes in the disk and 180 from the third hole 15 in the disk. Thus, when the striker 62 so contacts the surface 13 of the disk 10, the disk will be actuated for vibration into a fiexural mode with two nodal diameters, having a frequency of vibration that is higher than the other resonant frequency vibration of the disk.

As shown in FIG. 3, the striker 64 will strike the disk on a diameter thereof which is from two of the holes 15 and 135 from the third hole 15. Thus, if the leaf spring 63 is pulled rearwardly so that striker 64 contacts the disk, the disk can vibrate in a flexural mode about 2 nodal diameters with a frequency of vibration lower than the vibrations actuated by the striker 62.

The disk 10 of vibrator 10 shown in FIGS. 1 through 4 utilizes three radially extending holes 15. The axes of these holes as described in the above vibrator 10 have axes which are located at 90 apart and are diametrically or radially positioned midway between the surfaces 12 and 13. These holes have the same diameter and extend inwardly the same distance. It will be understood that 4 holes or fewer than 4 holes can be used. Hence, 1, 2, 3 or 4 holes or other dissymmetry could be employed to provide the 2 modes or resonants for the disk. As illustrated in the above figures the supporting pin 16 of disk 10 is mounted by a screw connection or some other suitable means on the member 52.

When striker 64 actuates the disk by having the spring 63 pulled rearwardly, and then released, the disk will be set into vibrations having nodal diameters D3 and D4, which pass through the axes of the holes 15. When the disk 10 shown in FIGS. 1 through 4 is actuated by a striking blow from actuator 62, the vibrator will be set into vibration having nodal diameters D1 and D2 which are midway between surface 12 and 13 and parallel thereto intersecting at the axes of the pin 16. In addition, these nodal diameters as illustrated in FIG. 3, are positioned at 45 to the axes of the holes 15.

Mounted on the lower side of the horizontally disposed plate 56 is a U-shaped spring having a base portion 71 which is fixedly secured by rivets, screws or some other suitable means to the lower portion of horizontally disposed plate 56. Integral with the lower base portion 71 are two outwardly and upwardly extending Spring arms 72 and 73. These arms are tapered and have near the outer ends thereof comically shaped contact members 74 and secured thereto. Spring arm 72 and spring arm 73 are tensioned so that they will normally be spaced from the disk 10, without contact from other external means. As illustrated in FIGS. 12 and 15, when spring arms 72 and 73 are forced inwardly the contact members 74 and 75 will contact disk 10. Contact member 75 will contact disk 10 midway between surfaces 12 and 13 in any plane defined by the axis of disk 10 and the axis of the middle hole 15 as illustrated in FIG. 3. Only three holes 15 are employed in the disk 10 shown in FIGS. 1 through 4 so that the contact with the disk by contact 75 can be at the center portion of the plane defined by diameter D4 in FIG. 3. Thus, the contact 75 would contact the disk 10 at the point and plane of maximum vibratory amplitude by vibrations caused by striker 62. When the arm 72, however, is forced inwardly so that contact 74 contacts the disk 10, it will contact the disk in a plane described by the axis of disk 10 in a plane passing through the axis at 45 to holes 15. In addition, the contact 74 will thus contact the disk midway between surfaces 12 and 13. Consequently, the contact of contact 74 with disk 10 is at a point of maximum vibratory amplitude when the disk is actuated by striker 64. As such, the contact 74, when in contact with disk 10 will tend to damp the vibrations effected by striker 64.

Actuating levers and are pivotally mounted for rotation about axis 57. Lever 90, includes a main channel body section 91 having an upper tap 92 extending outwardly therefrom. Suitable holes in the channel portion 91 are employed to mount the lever 90 on the shaft 57. As shown in FIGS. 1 and 2, a spring 93 is wound about the pin 57 and having one portion bearing against the upper portion of the cross member 51 and the other end secured to the inner portion of the channel member 91. This spring means 93 as shown in FIG. 2 tends to rotate the actuating lever 90 in a clockwise direction. Hence the normal position due to this spring action, is as illustrated in FIG. 2. In addition, the spring 93 tends to keep the lever 90 in aligned position and in contact with arm 54. Extending forwardly from the bottom portion of channel section 91 is a cam lever 95 and a tab 96 which is parallel to cam member 95. As can be seen from FIGS. 2 and 4 in solid lines and FIG. 3 in dotted lines, when the actuating lever 90 is in its normal rest position the upper edge of cam member 95 forces contact 75 into contact with disk 10. In this position, the inner portion of cam member 95 will contact spring arm 73 so that conical contactor 75 will be in contact with disk 10. Consequently, in this rest position the disk will be damped against vibrations caused by striker 62.

A U-shaped member 97 is pivotally mounted between tab 96 and lever arm 95 on a shaft 97a for rotation about shaft 97a. A cross bar 98, which overlaps tab 96 and lever 95, is secured to the upper portion of U-shaped member 97. A spring 99, mounted on shaft 97a has one end secured to the U-shaped member 97 and the other end secured to the lower side of lever arm 95 so as to tend to keep cross bar 98 in contact with lever arm 96 and tab 95. That is, as shown in FIG. 2, the spring 99 tends to rotate the U-shaped member 97 counterclockwise so as to keep cross bar 98 in contact with the rear edge of lever arm 95 and tab 96. The assembly described above can be mounted in a housing 100 such as by screws 101 passing through the housing 100 and into apertures in horizontal tabs 55 as shown in FIG. 2. The housing 100 is shown in dotted lines. Actuating lever buttons 102 shown in dotted lines are pivotally mounted on shaft 58 and have suitable stops by way of the side walls of apertures 103 in the housing as shown in FIG. 2. The lower portion of the front end of actuating lever 102 has a spherically shaped cam member 104 which is normally in contact with tab 92. The housing 100 has an opening 105 near the front of surface 12 of disk 10 so as to allow the ultrasonic signals caused by the vibration of disk 10 to pass out of housing 100. The housing 100, of course, can be made in two pieces so as to facilitate assembling the vibrating disk and other parts within the housing 100.

In the normal rest position, the arm 90 is as shown in FIGS. 2 and 4. In this position, spring 93 having one end contacting the cross bar 51 and the other end contacting the back of channel member 92 tends to hold the lever 90 clockwise so that the cam lever 95 is contacting the lower portion or edge of the cross bar 51. As such, the cam lever 95 holds the conical contactor 75 into contact with the disk, as shown in dotted lines in FIG. 3. In addition, spring 99 tends to hold cross bar 98 in constant with the lower portion of lever 95 and tab 96. As will be noted from FIG. 2, in such a position, the U member 97 as well as the cross bar 98 is forward of the lower portion of spring 61. Further, the contactor or striker element 62 along with spring 61 is in a rest position so that the spring 61 is vertically disposed and the front tip of contactor 62 is spaced from the surface '13 of disk 10 a predetermined distance.

If it is desired to produce an ultrasonic signal having the higher of the two frequencies, the tab 92 is pushed forwardly such as by depressing lever button 102 so that cam 104 rides on tab 92 thereby lowering the tab 92 to the horizontal position shown in FIG. 14. During the travel of tab 92 from its rest position to the horizontal position, the contactor 75 is first removed from contact with disk while the lower edge of spring 61 is being forced rearwardly by the U-shaped member 97. That is the pressure applied to arm 73 by lever arm 95 is removed so as to remove the contact 75 from contact with disk 10 while the lower portion of spring 61 is pulled rearwardly. After the contactor 75 is removed from contact with disk 10, further travel in a counterclockwise direction results in the lower edge of spring 61 coming out of contact with U member 97 in a rearwardmost position so as to effect a single striking blow by the striker 62 to the defined point on the rear surface 13 of disk 10. This sets up vibrations of the disk 10 in a flexural mode having the above described nodal diameters. Preferably the strength of the spring 61 and the distance between striker 62 and surface 13 is such that the travel effected by U-shaped member 97 permits only a single striking blow to the surface 13.

When the pressure on tab 92 is released spring 93 forces member 90 clockwise as viewed in FIG. 2. When U member 98 contacts the rear surface of spring 61 U member 98 rotates clockwise on member 90 as viewed in FIG. 13 so that member 98 will pass under spring 61. After member 98 passes under spring 61 spring 99 forces bar 98 back into contact with arm 95 and tab 96 to its normal rest position. The actuating lever 80 is similar in construction to the actuating lever 90. However, actuating lever 80 sequentially undamps the disk and actuates the disk for vibration of an ultrasonic signal having a frequency lower than the vibration actuated by actuating disk 90. The actuating lever 80 comprises a central C channel member 81 which is mounted for rotation at its upper end on shaft 57 by suitable apertures in either and both the arms of the channel member. Extending forwardly from and integral with channel member 81 is a tab member 82 similar in shape and size to the tab member 92. Extending forwardly from one of the channel sides of member 81 at the outer side of the resonator 10 is a cam lever 84 which when actuating means 80 is in a rest position contacts the angle section 76 of the spring leg 72 to force contactor 74 into position contacting disk 10. Extending outwardly from the other side of channel member 81 is a tab section 85 that is parallel to cam lever 84. A U-shaped member 86 is pivotally mounted on its legs on a shaft 87 which is secured between tab 85 and cam member 84. The crossbar of U section 86 has secured thereto a crossbar member 88 which extends outwardly from U member 86. The spring 89 is wound around shaft 87 with one end secured to cam member 84 and at the other end secured to the cross member of U member 86. This spring also tends to bring the cross member 88 in contact with the edges of tab member 85 and cam mem- 'ber 84 to normally assume a position as shown in FIG. 4. The mounting of this spring is similar to that shown in FIG. 2 for spring 99. A spring 83 is wound about shaft 57 and has one end secured to an aperture 81a in channel section 81 and the other end of this spring is secured to the upper portion of crossbar 51. This spring connection is similar to the connection described above for a spring member 93. The spring 83 is so tensioned and positioned so as to tend to rotate the lower portion of the actuating lever 80 forward so that cam arm 84 will effect damping of disk 10 by the contactor 74.

The actuating lever 80 is similar to that of actuating lever 90 so that in the rest position the cam lever 84 is forward to apply damping by contactor 74 contacting with disk 10, with the upper edge of cam lever 84 being in contact with the lower edge of crossbar 50 so as to limit further movement. Spring 83 tends to hold the actuating lever 89 in this forward position. The U member 86 is also held in position by spring 89 so that cross memher 88 contacts the lower edge of tap in a portion of cam lever 84. In this position, the circular or cylindrical surface presented by cross member 88 and the crossbar of U member 86, is forward of lower portion of spring 63. When tab 82 is pushed downwardly such as by a member similar to member 102 described above, the curved surface 86a will come into sliding contact with the lower portion of the leaf spring 63. As the tab is pushed downwardly, the cam member 84 will release spring arm 72 so that contactor 74 will come out of contact with the disk 10 and further rotation will pull the bottom of spring 63 rearwardly and subsequently release the spring to impart a single striking blow to the disk 10 at point C on surface 13. When the pressure on tab 82 is released, the actuating lever arm 80 returns to its rest position as illustrated in FIGS. 1 and 4 and the U member 86 with the cylindrical surface 86a pivots downwardly when it contacts the lower rear surface of spring 63 so as to once again resume its rest position in front of spring 63. Further as the pressure on tab 82 is released, cam arm 84 once again contacts spring arm 72 to again apply pressure thereto and to again place conical contactor 74 into contact with disk 10.

While we have described the above principles of our invention in connection with specific apparatus, it is to be clearly understood that this description is made only by way of example and not as a limitation of the scope of the invention as set forth in the objects thereof and in the accompanying claims.

We claim as our invention:

1. An ultrasonic transmitter comprising, a housing, mounting means supported within said housing, a flexural mode vibrator supported by said mounting means and resonant to vibrate at a first frequency about a first nodal diameter and at a second frequency about a second nodal diameter, striker means supported by said mounting means adjacent said vibrator, actuating means operatively associated with said striker means to actuate said vibrator into vibration about said first nodal diameter, damping means supported by said mounting means to effect damping of vibrations of said second frequency of said vibrator about said second nodal diameter during said vibrations about said first nodal diameter, and means operatively associated with said actuating means for effecting operation of said damping means.

2. An ultrasonic transmitter comprising, a housing, mounting means supported within said housing, a flexural mode vibrator supported by said mounting means and resonant to vibrate at a first frequency about a first nodal diameter and a second frequency about a second nodal diameter located perpendicular to said first nodal diameter, striker means supported by said mounting means adjacent said vibrator, actuating means operatively associated with said striker means, means operatively associated with said vibrator to actuate said vibrator into vibration about said first nodal diameter, damping means supported by said mounting means to simultaneously contact said vibrator adjacent said second nodal diameter to simultaneously effect damping of said vibrations of said vibrator about said second nodal diameter, and means operatively associated with said actuating means for effecting operation of said damping means.

3. An ultrasonic transmitter comprising, a housing, mounting means supported within said housing, a circularly shaped, flexural mode vibrator supported by said mounting means and resonant to vibrate at a first frequency about first and second nodal diameters disposed at thereto, and at a second frequency about a third nodal diameter and a fourth nodal diameter disposed at 90 thereto, striker means supported by said mounting means adjacent said vibrator, actuatin means operatively associated with said striker means to actuate said vibrator into vibrations about said first and second nodal diameters, damping means supported by said mounting means to simultaneously effect contact with said vibrator in a plane passing through the axis thereof and forming an angle of N+90 With said first nodal diameter Where N equals any integer and zero to effect damping of vibrations of said vibrator about said second nodal diameter, and means operatively associated with said actuating means for effecting operation of said damping means.

4. An ultrasonic transmitter comprising, a housing, mounting means supported within said housing a fiexural mode vibrator supported by said mounting means and resonant to vibrate at a first frequency about a first and a second nodal diameter and at a second frequency about a third and a fourth nodal diameter, striker means supported adjacent said vibrator, actuating means operatively associated with saidstriker means, to actuate said vibrator into vibration about said first and said second nodal diameters, damping means supported by said mounting means for simultaneously contacting said vibrator in a plane passing through the axis thereof and forming an angle of 45+N 90 With said first nodal diameter Where N equals any integer and zero to effect damping of vibrations of said vibrator about said second nodal diameter, and means operatively associated With said actuating means for effecting operation of said damping means.

5. An ultrasonic transmitter comprising, a housing, mounting means supported within said housing, a fiexural mode vibrator supported by said mounting means and resonant to vibrate at a first frequency about a first and a second nodal diameter, and a second frequency about a third and a fourth nodal diameter, striker means supported by said mounting means adjacent said vibrator,

8 actuating means operatively associated With said striker means to actuate said vibrator into vibration about said first and said second nodal diameters, damping means supported by said mounting means normally contacting said vibrator adjacent a plane passing through the axis of said vibrator and forming an angle of N with said first nodal diameter Where N equals any integer and zero to effect damping of vibrations of said vibrator about said second nodal diameter, and means responsive to said actuating means for removing said damping means from contact with said vibrator when said vibrator is actuated.

References Cited UNITED STATES PATENTS 2,153,725 4/1939 Sanders 84402 2,870,521 1/1959 Rudnick 2925.35 3,017,849 1/1962 Grossenheider 116-137 3,028,831 4/1962 Grundmann et a1. 116-137 3,068,834 12/1962 Kemeny 116137 3,077,856 2/1963 Rieth 116137 3,094,098 6/1963 Weiner 116137 3,118,423 1/1964 Schmid 116-137 3,157,151 11/1964 Whittaker et al. 116137 3,189,000 6/1965 Solners 116-137 3,194,209 7/1965 Nelkin et al. 116137 FOREIGN PATENTS 364,651 11/1922 Germany. 387,613 1/1924 Germany.

LOUIS J. CAPOZI, Primary Examiner. 

1. AN ULTRASONIC TRANSMITTER COMPRISING, A HOUSING, MOUNTING MEANS SUPPORTED WITHIN SAID HOUSING, A FLEXURAL MODE VIBRATOR SUPPORTED BY SAID MOUNTING MEANS AND RESONANT TO VIBRATE AT A FIRST FREQUENCY ABOUT A FIRST NODAL DIAMETER AND AT A SECOND FREQUENCY ABOUT A SECOND NODAL DIAMETER, STRIKER MEANS SUPPORTED BY SAID MOUNTING MEANS ADJACENT SAID VIBRATOR, ACTUATING MEANS OPERATIVELY ASSOCIATED WITH SAID STRIKER MEANS TO ACTUATE SAID VIBRATOR INTO VIBRATION ABOUT SAID NODAL DIAMETER, DAMPING MEANS SUPPORTED BY SAID MOUNTING MEANS TO EFFECT DAMPING OF VIBRATIONS OF SAID SECOND FREQUENCY OF SAID VIBRATOR ABOUT SAID SECOND NODAL DIAMETER DURING SAID VIBRATIONS ABOUT SAID FIRST NODAL DIAMETER, AND MEANS OPERATIVELY ASSOCIATED WITH SAID ACTUATING MEANS FOR EFFECTING OPERATION OF SAID DAMPING MEANS. 